From mboxrd@z Thu Jan 1 00:00:00 1970 From: jdesfossez@efficios.com (Julien Desfossez) Date: Sat, 30 Apr 2016 10:54:53 -0400 Subject: [lttng-dev] [PATCH lttng-modules v6 4/5] Extract the payload for epoll_ctl In-Reply-To: <765642146.74701.1462025964945.JavaMail.zimbra@efficios.com> References: <1461970404-27468-1-git-send-email-jdesfossez@efficios.com> <1461970404-27468-5-git-send-email-jdesfossez@efficios.com> <1938422112.74697.1462025832628.JavaMail.zimbra@efficios.com> <765642146.74701.1462025964945.JavaMail.zimbra@efficios.com> Message-ID: <20160430145453.GA20913@sinkpad.internal.efficios.com> On 30-Apr-2016 02:19:24 PM, Mathieu Desnoyers wrote: > ----- On Apr 30, 2016, at 10:17 AM, Mathieu Desnoyers mathieu.desnoyers at efficios.com wrote: > > > ----- On Apr 29, 2016, at 6:53 PM, Julien Desfossez jdesfossez at efficios.com > > wrote: > > > >> Map the operation to its name (EPOLL_CTL_*), extract the standard event > >> flags (EPOLL*) and output the data in two different formats: FD as an > >> int in decimal, and u64 in hex. The less standard event flags are not > >> extracted yet, but we extract the raw value in hex for more advanced > >> analyses. > >> > >> Here is an example output: > >> syscall_entry_epoll_ctl: { > >> epfd = 4, op_enum = ( "EPOLL_CTL_ADD" : container = 1 ), > >> fd = 0, event = { raw_events = 0x80000003, > >> events = { EPOLLIN = 1, EPOLLPRI = 1, EPOLLOUT = 0, EPOLLERR = 0, > >> padding = 0 }, > >> data_union = { u64 = 0x0, fd = 0 } } > >> } > >> > >> syscall_exit_epoll_ctl: { ret = 0 } > >> > >> Signed-off-by: Julien Desfossez > >> --- > >> .../syscalls/headers/syscalls_pointers_override.h | 140 +++++++++++++++++++++ > >> 1 file changed, 140 insertions(+) > >> > >> diff --git a/instrumentation/syscalls/headers/syscalls_pointers_override.h > >> b/instrumentation/syscalls/headers/syscalls_pointers_override.h > >> index 11d5f3d..59931df 100644 > >> --- a/instrumentation/syscalls/headers/syscalls_pointers_override.h > >> +++ b/instrumentation/syscalls/headers/syscalls_pointers_override.h > >> @@ -555,4 +555,144 @@ SC_LTTNG_TRACEPOINT_EVENT_CODE(ppoll, > >> ) > >> #endif /* defined(CONFIG_X86_32) || defined(CONFIG_X86_64) || > >> defined(CONFIG_ARM64) || defined(CONFIG_ARM) */ > >> > >> +#include > >> + > >> +SC_LTTNG_TRACEPOINT_ENUM(lttng_epoll_op, > >> + TP_ENUM_VALUES( > >> + ctf_enum_value("EPOLL_CTL_ADD", EPOLL_CTL_ADD) > >> + ctf_enum_value("EPOLL_CTL_DEL", EPOLL_CTL_DEL) > >> + ctf_enum_value("EPOLL_CTL_MOD", EPOLL_CTL_MOD) > >> + ) > >> +) > >> + > >> +#ifndef ONCE_LTTNG_TRACE_EPOLL_CTL_H > >> +#define ONCE_LTTNG_TRACE_EPOLL_CTL_H > >> + > >> +#define LTTNG_EPOLL_NRFLAGS (POLLHUP + 1) > >> +#define EPOLL_FLAGS_PADDING_SIZE (sizeof(uint8_t) * BITS_PER_BYTE) - \ > >> + ilog2(LTTNG_EPOLL_NRFLAGS - 1) > >> + > >> +/* > >> + * Only extract the values specified by iBCS2 for now. > >> + */ > >> +static struct lttng_event_field lttng_epoll_ctl_events_fields[] = { > >> + /* 0x0001 */ > >> + [ilog2(POLLIN)] = { > >> + .name = "EPOLLIN", > >> + .type = __type_integer(int, 1, 1, 0, __LITTLE_ENDIAN, 10, none), > >> + }, > >> + /* 0x0002 */ > >> + [ilog2(POLLPRI)] = { > >> + .name = "EPOLLPRI", > >> + .type = __type_integer(int, 1, 1, 0, __LITTLE_ENDIAN, 10, none), > >> + }, > >> + /* 0x0004 */ > >> + [ilog2(POLLOUT)] = { > >> + .name = "EPOLLOUT", > >> + .type = __type_integer(int, 1, 1, 0, __LITTLE_ENDIAN, 10, none), > >> + }, > >> + /* 0x0008 */ > >> + [ilog2(POLLERR)] = { > >> + .name = "EPOLLERR", > >> + .type = __type_integer(int, 1, 1, 0, __LITTLE_ENDIAN, 10, none), > >> + }, > >> + /* 0x0010 */ > >> + [ilog2(POLLHUP)] = { > >> + .name = "EPOLLHUP", > >> + .type = __type_integer(int, 1, 1, 0, __LITTLE_ENDIAN, 10, none), > >> + }, > >> + [ilog2(LTTNG_EPOLL_NRFLAGS)] = { > >> + .name = "padding", > >> + .type = __type_integer(int, EPOLL_FLAGS_PADDING_SIZE, 1, 0, > >> + __LITTLE_ENDIAN, 10, none), > >> + }, > >> + > >> +}; > >> + > >> +static struct lttng_event_field lttng_epoll_data_fields[] = { > >> + [0] = { > >> + .name = "u64", > >> + .type = __type_integer(uint64_t, 0, 0, 0, __BYTE_ORDER, 16, none), > >> + }, > >> + [1] = { > >> + .name = "fd", > >> + .type = __type_integer(int, 0, 0, 0, __BYTE_ORDER, 10, none), > >> + }, > >> +}; > >> + > >> +static struct lttng_event_field epoll_ctl_fields[] = { > >> + [0] = { > >> + .name = "data_union", > >> + .type = { > >> + .atype = atype_struct, > >> + .u._struct.nr_fields = ARRAY_SIZE(lttng_epoll_data_fields), > >> + .u._struct.fields = lttng_epoll_data_fields, > >> + } > >> + }, > >> + [1] = { > >> + .name = "raw_events", > >> + .type = __type_integer(uint32_t, 0, 0, 0, __BYTE_ORDER, 16, none), > >> + }, > >> + [2] = { > >> + .name = "events", > >> + .type = { > >> + .atype = atype_struct, > >> + .u._struct.nr_fields = ARRAY_SIZE(lttng_epoll_ctl_events_fields), > >> + .u._struct.fields = lttng_epoll_ctl_events_fields, > >> + } > >> + }, > >> +}; > >> +#endif /* ONCE_LTTNG_TRACE_EPOLL_CTL_H */ > >> + > >> +#if defined(CONFIG_X86_32) || defined(CONFIG_X86_64) || defined(CONFIG_ARM64) > >> || defined(CONFIG_ARM) > >> +#define OVERRIDE_32_epoll_ctl > >> +#define OVERRIDE_64_epoll_ctl > >> +SC_LTTNG_TRACEPOINT_EVENT_CODE(epoll_ctl, > >> + TP_PROTO(sc_exit(long ret,) int epfd, int op, int fd, > >> + struct epoll_event __user * uevent), > >> + TP_ARGS(sc_exit(ret,) epfd, op, fd, uevent), > >> + TP_locvar( > >> + struct epoll_event event; > >> + int err; > >> + ), > >> + TP_code_pre( > >> + tp_locvar->err = lib_ring_buffer_copy_from_user_check_nofault( > >> + &tp_locvar->event, uevent, sizeof(struct epoll_event)); > >> + ), > >> + TP_FIELDS( > >> + sc_exit(ctf_integer(long, ret, ret)) > >> + sc_in(ctf_integer(int, epfd, epfd)) > >> + sc_in(ctf_enum(lttng_epoll_op, int, op_enum, op)) > >> + sc_in(ctf_integer(int, fd, fd)) > >> + sc_in( > >> + ctf_custom_field( > >> + ctf_custom_type( > >> + .atype = atype_struct, > >> + .u._struct.nr_fields = ARRAY_SIZE(epoll_ctl_fields), > >> + .u._struct.fields = epoll_ctl_fields, > >> + ), > >> + event, > >> + ctf_custom_code( > >> + ctf_align(uint64_t) > >> + if (!tp_locvar->err) { > >> + ctf_integer_type(uint64_t, tp_locvar->event.data) > >> + ctf_integer_type(int, tp_locvar->event.data) > >> + ctf_integer_bitfield_type(uint32_t, > >> + cpu_to_le32(tp_locvar->event.events)) > > > > not sure why we reverse the endianness here ? It does not > > match the "__BYTE_ORDER" type description, and differs from > > the way raw_events fields is handled in the poll/ppoll instrumentation. > > also, why use a 32-bit integer rather than 16-bit as in poll/ppoll here ? Poll uses a short for the "events" field, but this field in struct epoll_event is a uint32_t, so we have to use the full 32 bits for the raw value in epoll_ctl and epoll_wait. Julien